• Title/Summary/Keyword: track-following control

Search Result 93, Processing Time 0.029 seconds

The Effects of Aqueous Extracts of Aconiti ciliare tuber on Functional Recovery after Sciatic Crushed Nerve Injury in Rats

  • Cho, Tae-Young;Song, Yun-Kyung;Lim, Hyung-Ho
    • The Journal of Korean Medicine
    • /
    • v.30 no.3
    • /
    • pp.39-50
    • /
    • 2009
  • Objective : The aim of this study was to evaluate the effects of Aconiti ciliare tuber on the descending pain and the recovery of locomotor function that results from sciatic crushed nerve injury in rats. Method : In order to assess the effects of the aqueous extract of Aconiti ciliare tuber on the recovery rate of locomotor function, we investigated the walking track analysis, and for the effects on the pain control we investigated brain-derived neurotrophic factor (BDNF) and inducible nitric oxide synthase (iNOS) expression in the sciatic nerve and on the expressions of c-Fos in the ventrolateral periaqueductal gray (vlPAG) region resulting from the sciatic crushed nerve injury in rats. Result : Treatment with Aconiti ciliare tuber significantly enhanced the SFIvalue, enhanced BDNF expression, decreased iNOS expression, and suppressed c-Fos expression. The present results showed that Aconiti ciliare tuber facilitated functional recovery following sciatic crushed nerve injury in rats. The recovery mechanisms of SFI by Aconiti ciliare tuber might be ascribed to the increase of BDNF expression for nerve regeneration and reinnervation and to the suppression of iNOS expression for inhibiting nerve inflammation. Conclusion : In this process it has been shown that Aconiti ciliare tuber can be used for pain control and functional recovery from peripheral nerve injury.

  • PDF

The Development of Sensor System and 3D World Modeling for Autonomous Vehicle (무인 차량을 위한 센서 시스템 개발 및 3차원 월드 모델링)

  • Kim, Si-Jong;Kang, Jung-Won;Choe, Yun-Geun;Park, Sang-Un;Shim, In-Wook;Ahn, Seung-Uk;Chung, Myung-Jin
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.6
    • /
    • pp.531-538
    • /
    • 2011
  • This paper describes a novel sensor system for 3D world modeling of an autonomous vehicle in large-scale outdoor environments. When an autonomous vehicle performs path planning and path following, well-constructed 3D world model of target environment is very important for analyze the environment and track the determined path. To generate well-construct 3D world model, we develop a novel sensor system. The proposed novel sensor system consists of two 2D laser scanners, two single cameras, a DGPS (Differential Global Positioning System) and an IMU (Inertial Measurement System). We verify the effectiveness of the proposed sensor system through experiment in large-scale outdoor environment.

Obstacle Avoidance of a Moving Sound Following Robot using Active Virtual Impedance (능동 가상 임피던스를 이용한 이동 음원 추종 로봇의 장애물 회피)

  • Han, Jong-Ho;Park, Sook-Hee;Noh, Kyung-Wook;Lee, Dong-Hyuk;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.20 no.2
    • /
    • pp.200-210
    • /
    • 2014
  • An active virtual impedance algorithm is newly proposed to track a sound source and to avoid obstacles while a mobile robot is following the sound source. The tracking velocity of a mobile robot to the sound source is determined by virtual repulsive and attraction forces to avoid obstacles and to follow the sound source, respectively. Active virtual impedance is defined as a function of distances and relative velocities to the sound source and obstacles from the mobile robot, which is used to generate the tracking velocity of the mobile robot. Conventional virtual impedance methods have fixed coefficients for the relative distances and velocities. However, in this research the coefficients are dynamically adjusted to elaborate the obstacle avoidance performance in multiple obstacle environments. The relative distances and velocities are obtained using a microphone array consisting of three microphones in a row. The geometrical relationships of the microphones are utilized to estimate the relative position and orientation of the sound source against the mobile robot which carries the microphone array. Effectiveness of the proposed algorithm has been demonstrated by real experiments.

A Study on Implementation of an Intelligent Video Surveillance System for Effective Education Method of Image Processing (효율적인 영상 처리 교육방법을 위한 지능형 영상 감시 시스템 구현에 관한 연구)

  • Park, Ho-Sik
    • The Journal of Korean Institute for Practical Engineering Education
    • /
    • v.2 no.1
    • /
    • pp.84-88
    • /
    • 2010
  • Recently, it is essential to have the system which can track down and identity the random object in the space in which security is a high priority. Due to the fact that we mentioned above, in this paper. We suggest the intelligent video surveillance system effective image-process-education in this paper. The experiment was conducted to check and track down the entering vehicle. And, Pan-Tilt-Zoom camera was used to obtain the enlarged image of the object while a vehicle was making stop in target area. As a result, the experiment has shown the data as following. When the object is in motion, success rate is 97.4%, while success rate is 91% when the object is motionless. By using the suggested system, effective image-process-education is should be achieved because the students who participate in the class can have simultaneous access to the system for real time image data and camera control.

  • PDF

Correction Factors for Modulus Calculation Equation used in Light Weight Deflectometer Considering Track Foundation (궤도노반 강성차이를 고려한 동평판재하시험(LWDT) 동탄성계수 산정공식 수정계수)

  • Choi, Chan Yong;Lee, Jin Wook;Lim, Yuijn;Cho, Hojin
    • Journal of the Korean Society for Railway
    • /
    • v.18 no.1
    • /
    • pp.53-62
    • /
    • 2015
  • LWDT was developed for use as an alternative technique to measure the stiffness of trackbed soils. In this study, numerical and theoretical analyses of LWDT's acting mechanism were performed. The effectiveness of the adapted elastic formula used for calculation of the dynamic modulus, Evd, was investigated theoretically and also numerically by running ABAQUS analysis. The minimum thickness of the upper layer is proposed based on the analysis. Correction factors for the formula of elastic modulus are also proposed in this study. In the future, following field test results and laboratory mechanical tests such as the resonant column test, a guideline for the use of LWDT as a standard test protocol in track construction sites, as a measuring tool for the degree of compaction and/or stiffness and dynamic modulus, will be proposed based on this analysis.

A Load-Sharing Scheme using SCTP Multi-homing (SCTP 멀티호밍 특성을 활용한 부하 분산 기법)

  • Song Jeonghwa;Lee Meejeong
    • Journal of KIISE:Information Networking
    • /
    • v.31 no.6
    • /
    • pp.595-607
    • /
    • 2004
  • Networks often evolve to provide a host with multiple access points to the Internet. In this paper, we propose a transport layer load distribution mechanism utilizing the multiple network interfaces simultaneously. We specifically propose an extension of Stream Control Transmission Protoco1 (SCTP) to have load sharing over multiple network interfaces. We named the particular service provided by the Proposed load sharing mechanism to be LS (Load Sharing) mode service. LS mode service is based on the following four key elements: (i) the separation of flow control and congestion control, (ii) congestion window based striping, (iii) redundant packet retransmission for fast packet loss recovery, (iv) a novel mechanism to keep track of the receiver window size with the SACKS even if they arrive out-of-order. Through simulations, it is shown that the proposed LS mode service can aggregate the bandwidth of multiple paths almost ideally despite of the disparity in their bandwidth. When a path with a delay of 100% greater is utilized as the second path, the throughput is enhanced about 20%.

Active Control of a New Cargo Handling System Adapted for Time-Varying Tide (조수간만의 차를 고려한 새로운 하역 시스템의 능동 제어)

  • Hyoung-Seok Kim;Dar-Do Chung;Seung-Bok Choi;Jae-Wook Lee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.36 no.2
    • /
    • pp.61-71
    • /
    • 1999
  • This paper resents a novel cargo system adapted for a sea port subjected to severe time-varying tide. The proposed system can perform loading or unloading by using a sort of hydraulic elevator associated with real-tim position control. As a preliminary phase, a small-sized model of the cargo system is designed and constructed. The model consists of three principal components ; container palette transfer(CPT) car, platform with lifting columns and cargo ship. The platform activated by the electro-rheological(ER) valve-cylinder is actively controlled to track the position of the cargo ship subjected to be varied due to the time-varying tide and wave motion. Following the derivation of the dynamic model for the platform and cargo ship motions, an appropriate control scheme incorporating time sequence and PID(proportional-integral-derivative) controller is formulated and implemented. Both the simulated and the measured control results are presented to demonstrate the effectiveness of the proposed cargo system.

  • PDF

Design of Output Regulator for Rejecting Periodic Eccentricity Disturbance in Optical Disc Drive

  • Shim, Hyung-Bo;Kim, Hyung-Jong;Chung, Chung-Choo
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.452-457
    • /
    • 2003
  • An add-on type output regulator is proposed in this paper. By an add-on controller we mean an additional controller which operates harmonically with a pre-designed one. The role of the add-on controller is to reject a sinusoidal disturbance of unknown magnitude and phase but with known frequency. Advantages of the proposed controller include that (1) it can be used only when the performance of disturbance rejection needs to be enhanced, (2) when it is turned on or off, unwanted transient can be avoided (i.e., bumpless transfer), (3) it is designed for perfect disturbance rejection not just for disturbance reduction, (4) ability for perfect rejection is preserved even with uncertain plant model. This design may be promising for optical disc drive (ODD) systems in which disc eccentricity results in a sinusoidal disturbance. For ODD systems, the sensitivity function obtained by the pre-designed controller, which may have been designed by the lead-lag, $H_{\infty}$, or DOB (disturbance observer) technique, does not change much with the add-on controller except at the frequency of the disturbance. Since the add-on controller does the job of rejecting major eccentricity disturbance, the gain of the pre-designed controller does not have to be too high.

  • PDF

Position Control of Mobile Robot for Human-Following in Intelligent Space with Distributed Sensors

  • Jin Tae-Seok;Lee Jang-Myung;Hashimoto Hideki
    • International Journal of Control, Automation, and Systems
    • /
    • v.4 no.2
    • /
    • pp.204-216
    • /
    • 2006
  • Latest advances in hardware technology and state of the art of mobile robot and artificial intelligence research can be employed to develop autonomous and distributed monitoring systems. And mobile service robot requires the perception of its present position to coexist with humans and support humans effectively in populated environments. To realize these abilities, robot needs to keep track of relevant changes in the environment. This paper proposes a localization of mobile robot using the images by distributed intelligent networked devices (DINDs) in intelligent space (ISpace) is used in order to achieve these goals. This scheme combines data from the observed position using dead-reckoning sensors and the estimated position using images of moving object, such as those of a walking human, used to determine the moving location of a mobile robot. The moving object is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Using the a priori known path of a moving object and a perspective camera model, the geometric constraint equations that represent the relation between image frame coordinates of a moving object and the estimated position of the robot are derived. The proposed method utilizes the error between the observed and estimated image coordinates to localize the mobile robot, and the Kalman filtering scheme is used to estimate the location of moving robot. The proposed approach is applied for a mobile robot in ISpace to show the reduction of uncertainty in the determining of the location of the mobile robot. Its performance is verified by computer simulation and experiment.

An Improved Tracking Servo System in Optical Disk Drives (광디스크 드라이브의 개선된 트래킹 서보 시스템)

  • Lee, Tae-Gyu;Jeong, Dong-Seul;Chung, Chung-Choo
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.44 no.4 s.316
    • /
    • pp.67-73
    • /
    • 2007
  • An optical pick up generally has coupled dynamics between focusing and tracking servos. The coupled dynamics reduces tracking performance of optical disk drives. A conventional control method is holding the previous tracking control command in the presence of surface defect. The method has a long settling time. If the defective area is getting larger, objective lens will get away from the following track. In order to overcome this problem, this paper proposed a new control method for optical disk drives based on a prediction of tracking error and focusing error. We present how to compensate the coupled dynamics so that reduced setting time is achieved. It is verified by experiments that the proposed method brings an improved performance in the presence of surface defect as well as in the normal operating condition.